VB.NET CDbl Example – Code Sample Syntax
VB.NET CDbl Example – Code Sample Syntax
Purpose: – Illustrates using VB.NET CDbl Code Example.
Description:
Converts positive and negative numbers into double data type
Syntax:
CDbl(expression)
CDbl(expression)
Parameters | Description | expression | -1.79769313486231570E+308 through -4.94065645841246544E-324 for negative values; 4.94065645841246544E-324 through 1.79769313486231570E+308 for positive values. |
---|
Result Data Type | Description | double | double precision floating point number |
---|
Step 1: Click Visual Basic to Cut-n-paste code into clsCDbl.vb
Public Class clsCDbl Public Sub Main() '**************************************************************************************** ' Purpose: Converts positive and negative numbers into double data type ' ' Syntax: CDbl(expression) ' ' Parameter1: expression - -1.79769313486231570E+308 through ' -4.94065645841246544E-324 for negative values; ' 4.94065645841246544E-324 through ' 1.79769313486231570E+308 for positive values. ' ' Result: double - double precision floating point number ' ' '**************************************************************************************** ' This example is from http://idealprogrammer.com Console.WriteLine("Example #1: CDbl(expression)") Dim double1 As Double = CDbl(1.33) Console.WriteLine(double1) ' Returns 1.33 'write blank line to make output easier to read Console.WriteLine() Console.WriteLine("Example #2: CDbl(expression)") Dim Double2 As Double = CDbl(-3.4) Console.WriteLine(Double2) ' Returns -3.4 'write blank line to make output easier to read Console.WriteLine() Console.WriteLine("Example #3: CDbl(expression)") Dim Double3 As Double = CDbl(5) Console.WriteLine(CDbl(Double3)) ' Returns 5 'Prevent console from closing before you press enter Console.ReadLine() End Sub End Class |
Step 2: Click Visual Basic to Cut-n-paste code into Module1.vb
Module Module1 Sub Main() Dim myclsCDbl As New clsCDbl myclsCDbl.Main() End Sub End Module |
Prerequistes:
- Install Visual Basic (Express or Standard Edition)
- Install SQL Server Express
- Download Northwind and pubs Database
- Attach Northwind Database to Databases in Sql Express
- Attach pubs Database to Databases in Sql Express
Notes:
- Console Application is used to simplify things, but Windows Forms or Web Forms could also be used
- You can build a library of syntax examples by using same project over and over and just commenting out what you do not want to execute in Module1.vb
Instructions:
- Use Visual Basic 2010 Express or Standard Edition
- Create new project;
- Click File/New Project
- Select Console Application Template
- Select Visual Basic for Language
- name of project could be VBNET_Syntax.
- Add New folder named “Functions”
- Right-click project name in solution explorer;
- add new folder;
- name of folder could be: Functions
- Add New subfolder named “ConversionFunctions”
- Right-click Functions folder in solution explorer;
- add new folder;
- name of folder could be: ConversionFunctions
- Add New subfolder named “TypeConversionFunctions”
- Right-click ConversionFunctions folder in solution explorer;
- add new folder;
- name of folder could be: TypeConversionFunctions
- Add Class Named clsCDbl to TypeConversionFunctions folder
- Right-click TypeConversionFunctions folder;
- add new item;
- Select class
- Class name could be clsCDbl
- Click on Visual Basic in code in step 1 above to copy code into clsCDbl.vb
- Click on Visual Basic in code in step 2 above to copy code into Module1.vb
- Click green arrow or press F5 to run program